5 of 7Brabus adds a new crank and a few other goodies to the Mercedes V12.

Photo by Brabus

6 of 7The V12 comes from the S600.

Photo by Brabus

7 of 7Brabus upgraded the C63 AMG to 781 hp.

Photo by Brabus

Brabus will show off the Bullit Coupe 800 at its stand at the Geneva motor show. The German tuning house used the Mercedes-Benz C63 AMG as its donor car.

The Coupe 800 will deliver 788 hp (800 PS) and an electronically limited 811 lb-ft of torque. Brabus does this by tossing the stock 6.2-liter V8 in favor of the twin-turbocharged V12 engine from an S600. The company increases displacement from 5.5 liters to 6.3 liters by installing a new crankshaft with a longer stroke and larger, forged pistons and boring out the cylinders.

The inlet side of the engine has a larger header casting that gets its oxygen from the ram air scoop in the hood. Two custom exhaust manifolds are added, with turbochargers and four water-to-air intercoolers. The exhaust has a driver-controlled butterfly valve to customize the sound.

After Brabus works its magic the company claims the Coupe 800 can go from 0 to 60 mph in 3.7 seconds. That's 0.7 second faster than the stock car. The run from 0-to-186 mph (300 kph) takes 23.8 seconds, and when it's all over, the car will top 230 mph.

Power is funneled through the back wheels via a reinforced seven-speed automatic transmission and a Brabus limited-slip differential with a locking rate of 40 percent.

The company says the engineers spent extensive time in the wind tunnel with the car, tweaking aerodynamics at speed. The carbon-fiber front spoiler reduces lift while the front air inlets not only cool the radiator and brakes, but also help air exit as quickly as possible. The rear wing and new diffuser provide more stability.

Brabus developed a custom suspension setup for the Coupe 800, in cooperation with partner Bilstein. The gas shocks at the front and rear offer 10 settings for jounce and rebound, and sport sway bars reduce body roll when cornering.

To slow things down, Brabus installs a set of 12-piston front brakes with six-piston rears. Vented and grooved brake discs measure 15 inches in front and 14.2 inches in back.

The cost of this Mercedes-based hypercar is about $500,000, give or take. For a few euros more, Brabus says the car can also be built off the Black Series version of the C63.